Intravenous and intra-arterial catheter-cannula devices are used to deliver drugs, fluids or medical devices into the circulatory system of patients. A catheter, cannula or sheath is inserted into a patient's vein or artery, typically using an introducer needle. After the device is inserted, the needle is withdrawn and some other instrument or device is inserted through the catheter or cannula.
Catheters include a broad variety of tubular devices that are inserted into blood vessels to provide access to the vascular system of a living being as well as therapeutic devices that are used to treat ailments of the body via the vascular system. Catheters include but are not limited to any tubular device that is inserted into a living body through which fluid may exit the body when the device is inserted into the body such as introducers and sheaths having hemostatic valves.
The vascular system is under constant but varying pressure in a living being. The arterial system is under higher pressure than the venous system. While placing the other device into the catheter or cannula, blood or other bodily fluid can back flow out of the end of the catheter or cannula. This is particularly true when an artery is accessed due to the higher arterial blood pressure as compared to venous blood pressure. Often, a guidewire is inserted through the catheter or cannula assembly that has been prelocated in the femoral artery in a patient's groin to allow the insertion of instruments complex procedures to be performed in the heart or the arteries surrounding the heart. When a guidewire is present in a sheath often a hemostatic valve cannot be closed to prevent leakage of blood from the accessed blood vessel.
Intravascular instruments need to be switched out during these procedures, often allowing blood to flow out of the opening at the proximal end of the catheter. Prior art methods of closing the catheter end, such as ball valve assemblies and one-way valves cannot be operated with a guide wire still in place.